Segmental retaining wall system

ABSTRACT

A segmental retaining wall system comprising a plurality of wall blocks. Each wall block comprises an interior face for forming an interior surface of a segmental retaining wall, an exterior face for forming an exterior surface of the segmental retaining wall, first and second sides that extend from said exterior face to said interior face, a top surface, and a bottom surface. In addition, a plurality of wall blocks include apparatus for retaining a reinforcement member to the segmental retaining wall. In one arrangement, this apparatus comprises a channel that is defined by a front wall, a rear wall, and a channel bottom surface. This channel is provided in one of the faces and surfaces, and includes an inwardly extending shoulder.

This is a continuation-in-part of U.S. patent application Ser. No.09/049,627, filed Mar. 27, 1998 now U.S. Pat. No. 6,089,793.

FIELD OF THE INVENTION

The invention relates generally to earth retaining walls. Moreparticularly, the invention relates to a segmental retaining wall systemcomprising retaining means for attaching reinforcement members to theretaining wall.

BACKGROUND OF THE INVENTION

Segmental retaining walls commonly are used for architectural and sitedevelopment applications. Such walls are subjected to very highpressures exerted by lateral movements of the soil, temperature andshrinkage effects, and seismic loads. Therefore, the wall is often tiedinto the backfill soil, typically with tensile reinforcement members.Usually, elongated structures, commonly referred to as geogrids orreinforcement fabrics, are used to provide this reinforcement. Geogridsoften are configured in a lattice arrangement and are constructed of ametal or plastic, while reinforcement fabrics are constructed of a wovenor non-woven polymer fibers or plastics. These reinforcement memberstypically extend rearwardly from the wall and into the soil to stabilizethe soil against movement and thereby create a more stable soil masswhich results in a more structurally secure retaining wall.

Although several different forms of reinforcement members have beendeveloped, difficulties remain with respect to attachment of the membersto retaining walls. In particular, the reinforcement members can shiftout of position and be pulled away from the retaining wall due tomovement of the soil. This difficulty especially can be problematic inareas of high seismic activity where a poorly secured gravity wall cantopple. In response to this problem, several current retaining wallsystems have been developed to retain geogrid reinforcement members. Inone such system, rake shaped connector bars are positioned transverselyin the center of the contact area between adjacent stacked blocks withthe prongs of the connector bars extending through elongated aperturesprovided in the geogrid in position under normal conditions, this systemof attachment provides a substantial drawback. Specifically, thegeogrids of this system only extend along the back halves of the contactareas between the blocks. Although the geogrids are relatively thin,this partial insertion of the geogrids can cause the retaining wall tobow outwardly due to the aggregate thickness of the geogrids. As can beappreciated, this outward bowing can be substantial with tall retainingwalls that require a multiplicity of geogrids. Aside from creating theimpression of instability, this condition increases the likelihood ofwall failure, particularly in response to seismic activity.

From the above, it can be appreciated that it would be desirable to havea mechanically stable wall system having secure retaining means formaintaining connection of reinforcement members to the retaining wall.

SUMMARY OF THE INVENTION

Briefly described, the present invention relates to a segmentalretaining wall system. This system comprises a plurality of wall blocks.Each wall block comprise an interior face for forming an interiorsurface of a segmental retaining wall, an exterior face for forming anexterior surface of the segmental retaining wall, first and second sidesthat extend from said exterior face to said interior face, a topsurface, and a bottom surface. In addition, the wall block includesretaining means for retaining a reinforcement member to the segmentalretaining wall. In one arrangement, these retaining means comprises achannel that is defined by a front wall, a rear wall, and a channelbottom surface. This channel is provided in one of the faces andsurfaces of the block, and preferably includes at least one inwardlyextending shoulder.

The objects, features, and advantages of this invention will becomeapparent upon reading the following specification, when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a retaining wall formed in accordancewith the present invention.

FIG. 2 is a perspective front view of a wall block used in the wallshown in FIG. 1.

FIG. 3 is a perspective rear view of the wall block shown in FIG. 2.

FIG. 4 is a detail view of a channel provided in a top surface of a wallblock.

FIG. 5 is a detail view of a flange provided on a bottom surface of awall block.

FIG. 6 is a side view of a reinforcement member retaining bar.

FIG. 7 is a partial side view of a wall block depicting insertion of theretaining bar shown in FIG. 6 over a reinforcement member within achannel of the wall block.

FIG. 8 is a cross-sectional side view of a retaining wall constructed inaccordance with the present invention.

FIG. 9 is a detail view showing the retention of a reinforcement memberbetween adjacent stacked wall blocks.

DETAILED DESCRIPTION

Referring now in more detail to the drawings, in which like numeralsindicate corresponding parts throughout the several views, FIG. 1illustrates the general concept of a segmental gravity retaining wall 10constructed in accordance with the present invention. As depicted inthis figure, the retaining wall 10 comprises a plurality of wall blocks12 that are stacked atop each other in ascending courses 14. Whenstacked in this manner, the wall blocks 12 together form an exterior ordecorative surface 15 which faces outwardly away from the soil, and aninterior surface 17 which faces inwardly toward the soil.

Generally speaking, the wall blocks 12 are substantially identical insize and shape for ease of block fabrication and wall construction.Accordingly, each block 12 typically is configured so as to mate withvertically adjacent blocks when the blocks are stacked atop one anotherto form the retaining wall 10. Referring to FIGS. 2 and 3, each wallblock 12 comprises an exterior face 24, an opposed interior face 26, atop surface 28, a bottom surface 30, and two opposed sides 32. Becausethe exterior faces 24 of the blocks 12 form the exterior surface 15 ofthe retaining wall 10, the exterior faces typically are provided with anornamental texture or facing to create a visually pleasing facade. Also,the exterior face 24 of each wall block 12 is preferably sloped inwardlyfrom the bottom surface 30 to the top surface 28 in an incline ratio ofapproximately 30 to 1. This inward slope of each block exterior surface15 creates an aggregate inward slope effect over the entire retainingwall 10 which counteracts the outward leaning impression commonlycreated by such walls when viewed by the observer. Contrary to theexterior faces 24, the interior faces 26 of the wall blocks 12 normallyare configured in an upright or vertical orientation and, therefore,form an upright interior surface 17 of the retaining wall 10.

The top and bottom surfaces 28 and 30 of each block 12 typically areparallel to each other so that, when stacked on top of one another, anupright wall 10 is formed. Similarly, the opposed sides 32 typically areparallel to each other. However, the opposed sides 32 can be inwardly oroutwardly tapered from the exterior face 24 of the block 12 to theinterior face 26 of the block to form curved walls of nearly any shape.Preferably, the wall blocks 12 further include interior openings 34which reduce the amount of concrete or other materials needed tofabricate the blocks and reduce the weight of the blocks to simplifywall construction. Although depicted in the figures as being arranged ina horizontal orientation, these openings could be arranged in a verticalorientation, if desired.

As mentioned above, the wall blocks 12 typically comprise retainingmeans for attaching reinforcement members (e.g., geogrid) to theretaining wall 10. These retaining means include a channel 16.Typically, each block 12 has a channel 16 provided in its top surface28, although alternative placement is feasible. By way of example, thechannel 16 alternatively could be provided in the bottom surface 30 orthe interior face 26 of the wall block 12. When provided in the interiorface 26 of the block 12, the channel 16 can be arranged eitherhorizontally or vertically therein, although horizontal placement ispreferred. When the channel 16 is provided in the top surface 28,however, the channel normally extends transversely across the block 12from one side 32 of the block to the other, usually parallel to theexterior surface 15 of the block 12. As illustrated in FIG. 4, thechannel 16 is defined by a front wall 36, a rear wall 38, and a channelbottom surface 40. The front wall 36 can include a shoulder 42 thatextends inwardly toward the interior face 26 of the wall block 12. In apreferred embodiment, the shoulder 42 is arranged as a curved lip suchthat the channel comprises a first substantially arcuate edge 44.

Positioned opposite the front wall 36, the rear wall 38 of the channel16 preferably similarly includes an inwardly extending shoulder 45. Therear wall shoulder 45 preferably is arranged as a curved lip so as toform a second substantially arcuate edge 46 of the channel 16. Althoughthe shoulders 42, 45 have been described herein as being arranged ascurved lips, it will be apparent from the present disclosure that theseshoulders alternatively could be arranged as inwardly extending flangesor other such protrusions. Furthermore, depending upon the particularimplements used to retain the reinforcement members, the placement ofthe channel 16, and the degree of block-to-block locking desired, thewalls 36, 38 can be formed without such shoulders 42, 45 to simplifyblock construction. For example, if the channel 16 is not used tofacilitate block-to-block locking, the front wall 36 can besubstantially planar in shape in that it does not serve the retainingfunction that the rear wall 38 serves (see FIG. 9).

Where block-to-block locking is desired, the front wall 36 typicallyincludes a shoulder 42 that is adapted to receive a flange 18 thatextends from the block 12. In a preferred embodiment, the flange 18 isprovided on the bottom surface 30 of the block 12 and, like the channel16, extends transversely from one side 32 of the block to the other side32. As is illustrated in FIG. 5, the flange 18 is defined by a frontsurface 48, a rear surface 50, and a bottom surface 52. Both the frontsurface 48 and the rear surface 50 extend toward the exterior face 24 ofthe wall block 12 such that the entire flange 18 extends towards theexterior face 24 of the block. To provide for the interlocking betweenvertically adjacent wall blocks 12, the blocks can be placed on top oftower wall blocks 12 such that the flanges 18 extend into the channels16. Once so situated, the upper wall blocks can be urged forward alongthe lower blocks so that the front surfaces 48 of the flanges 18 abutthe front walls 36 of the channels 16. This abutment prevents the blockfrom leaning forward or toppling. As is known in the art, alternativelocking means can be used such as pin and cavity, protrusion and cavity,mating/aligning systems. Example systems include these of U.S. Pat. Nos.4,914,876, 5,257,880, 5,607,262, and 5,827,015.

The retaining means of the disclosed system typically further include areinforcement member retaining bar 22, shown most clearly in FIG. 6. Asindicated in this figure, the retaining bar 22 specifically is sized andconfigured to fit within the channel 16. In a preferred arrangement, theretaining bar 22 has a plurality of different surfaces: a top surface54, a bottom surface 56, a first upright surface 58, a second uprightsurface 60, a first oblique surface 62, and a second oblique surface 64.Normally, the top surface 54 and the bottom surface 56 are parallel toeach other as are the first oblique surface 62 and the second obliquesurface 64. Similarly, the first upright surface 58 and the secondupright surface 60 typically are parallel to each other such that thefirst upright surface extends perpendicular from the top surface 54 andthe second upright surface extends perpendicularly from the bottomsurface 56. Configured in this manner, the retaining bar 22 can bepositioned on top of a reinforcement member 20 in the channels 16 byinserting the retaining bar into the channels with the second uprightsurface 60 forward, and twisting the bar downwardly into place asdepicted in FIG. 7. In that the bar 22 is designed to fit closelybetween the front and rear walls 36 and 38 of the channels 16 when inplace, a longitudinal notch 46 is provided in the channel 16 toaccommodate the second upright surface 60 during the twisting anddownward insertion of the bar.

Once correctly inserted within the channel 16, the first upright surface58 and the second oblique surface 64 of the retaining bar 22 hold thereinforcement member 20 against the front and rear walls 36 and 38 ofthe channel, respectively, as shown in FIG. 7. In embodiments in whichthe flange 18 is not provided, the channel 16 can have a relativelyshallow depth dimension. The retaining bar 22 prevents the reinforcementmember 20 from being pulled out from the retaining wall 10.Specifically, when a tensile force is applied to the reinforcementmember 20 from the soil side of the retaining wall 10, the retaining bar22 is rotated within the channel 16 to cause the reinforcement member tobe clamped by member 20 to the sides of the channel, locking thereinforcement member in place. In that the amount of pressure that isapplied on the retaining bar 22 is not large, the retaining bar can beconstructed of a polymeric material such as nylon 6,6 or high densitypolyethylene. Use of such a polymeric material provides the additionaladvantage of providing for a lightweight, inert retaining bar.

The system of the present invention can be used to construct any numberof different configurations of segmental retaining walls. FIG. 8illustrates one example of such a retaining wall 66. To construct such awall 66, a leveling pad 68 is laid to provide a foundation upon which tobuild the wall. Typically, this leveling pad 68 comprises a layer ofcompacted, crushed stone that is embedded under the soil to protect thewall foundation. Once the leveling pad 68 is laid and compacted, aplurality of starting blocks 70 are aligned along the length of the pad.Each of the starting blocks 70 is provided with a channel in its topsurface. However, since there are no lower courses with which to engage,the starter blocks 70 are not provided with flanges, or existing flangeson the block can be broken off with a hammer. Additionally, specialstarting blocks (if used) can be relatively short in height, typicallybeing approximately half as tall as the wall blocks. Although suchstarting blocks 70 typically are used in the starting course of theretaining wall, it is to be noted that the standard wall blocks 12 couldbe used to form this course, if desired.

After the starting course has been formed with either the startingblocks 70 or wall blocks 12, the next course of blocks can be laid. Thewall blocks 12 are placed on top of the blocks of the starting coursewith the flanges 18, if provided, extending into the channels 16 of thelower blocks. As can be appreciated from FIG. 8, and with reference toFIGS. 4 and 5, the front surfaces 48 of the flanges mate with the frontwall shoulders 42 of the channels 16 such that each flange 18 extendsunderneath the shoulders. This mating relationship holds the wall block12 in place atop the lower blocks and prevents the wall block fromtipping forward, thereby providing integral locking means for the block.

Once the first wall course has been formed atop the starting course,backfill soil, S, can be placed behind the blocks 12. Typically, anon-woven filter fabric 72 is provided between the wall 66 and thebackfill soils to prevent the introduction of particulate matter betweenthe courses of blocks due to water migration within the soil.Alternatively, a layer of gravel aggregate can be provided between thewall and the soil to serve the same function. Additional ascendingcourses thereafter are laid in the manner described above. Althoughalternative configurations are possible, a reinforcement member 20typically is laid between every other course of blocks 12 as indicatedin FIG. 8. It will be appreciated, however, that greater or fewerreinforcement members 20 can be provided depending upon the particularreinforcment needs of the construction site. Preferably, thesereinforcement members 20 are composed of a flexible polymeric fabric. Asdescribed above, the reinforcment members 20 are positioned so that theyextend from the exterior surface 15 of the retaining wall, into thechannel 16, and past the exterior surface 17 of the retaining wall toextend into the soil. As shown most clearly in FIG. 9, a reinforcementmember retaining bar 22 is placed on top of the reinforcement member 20in the channel 16. When the next course of blocks 12 is laid on top ofthe lower course, the flange 18 of the upper blocks extends into thechannel 16 adjacent the retaining bar.

Construction of the retaining wall 66 continues in this manner until thedesired height is attained. As indicated in FIG. 8, the inward slope ofthe wall blocks 12 creates a net inward slope of the retaining wall.Additionally, the configuration the blocks 12 creates an aestheticallypleasing stepped appearance for the exterior surface of the wall 66.Where the full height of a wall block 12 is unnecessary or not desired,short wall blocks 74 can be used to form the top course. Typically,these short wall blocks 74 are approximately half the height of thestandard wall blocks 12. Once the retaining wall 66 has been raised tothe required height, cap blocks 76 can be used to complete the wall. Asshown in FIG. 8, these cap blocks 76 can be provided with a flange 18,but do not have an upper channel in that further construction will notbe conducted. Normally, the cap blocks 76 are fixed in position withconcrete adhesive and the top surface of the cap blocks are providedwith an ornamental pattern similar to the exterior faces of the blocks.The cap block 76 is designed to extend out over the lower block toprovide a lip for aesthetics. Additionally, a subsurface collector drain78 can be provided within the backfill soil to remove excess watercollected therein.

While preferred embodiments of the invention have been disclosed indetail in the foregoing description and drawings, it will be understoodby those skilled in the art that variations and modifications thereofcan be made without departing from the spirit and scope of the inventionas set forth in the following claims. For instance, although particularblock configurations have been identified herein, persons havingordinary skill in the art will appreciate that the concepts disclosedherein, in particular the retaining means described herein, areapplicable to prior and future wall block designs.

1. A wall block for use in a segmental retaining wall system, said wallblock comprising: an interior block face for forming an interior surfaceof a segmental retaining wall; an exterior block face for forming anexterior surface of the segmental retaining wall; first and second blocksides that extend from said exterior block face to said interior blockface; a block top surface and having a lock channel formed therein, thelock channel being defined by a channel front wall, a channel rear wall,and a channel bottom surface, the lock channel extending transverselyacross the block top surface from the first block side to the secondblock side, wherein the channel front wall forms a first shoulder thatextends towards the interior block face so as to overhang a portion ofthe channel front wall, wherein the channel rear wall forms a secondshoulder that extends towards the exterior block face so as to overhanga portion of the channel rear wall, and wherein the shoulders are spacedapart and run generally parallel to each other along the lock channel; ablock bottom surface; and a channel defined by a front wall, a rearwall, and a channel bottom surface and extending across one of saidfaces and surfaces, said rear wall including an inwardly extendingshoulder.a lock flange on the bottom surface of the block, the lockflange being defined by a flange front surface extending from the blockbottom surface, a flange rear surface extending from the block bottomsurface, and a flange bottom surface extending between the flange frontand rear surfaces, the lock flange extending transversely across theblock bottom surface in substantially the same direction as the lockchannel, the lock flange being sized, shaped, and positioned so that theflange will fit into the lock channel of a similarly configured wallblock in an adjacent lower course when the lock flange is passeddownwardly through the space between the first and second shoulders ofthe similarly configured wall block and into the lock channel of thatwall block from above, and wherein the flange front surface includes aportion that is sized and shaped so as to engage the first shoulder ofthe lock channel of the similarly configured block either directly, orindirectly if a portion of a soil reinforcement member is interposedbetween the flange front and the first shoulder, such that when the wallblock is stacked atop the similarly configured block the wall block isproperly aligned thereon.
 2. The wall block of claim 1, wherein saidchannel is formed in said top surface of said wall block. the flangefront surface includes a portion that extends towards the exterior blockface so as to overhang a portion of the flange front surface and issized and shaped so as to engage the first shoulder of the lock channelof the similarly configured block either directly, or indirectly if aportion of the soil reinforcement member is interposed between theflange front surface and the first shoulder, such that when the wallblock is stacked atop the similarly configured block, the engagementbetween the lock flange and the lock channel of the similarly configuredblock resists forward leaning or toppling of the wall block.
 3. The wallblock of claim 2, wherein said channel extends transversely across saidtop surface from said first side to said second side of said wall block.4. The wall block of claim 1, wherein said rear wall the second shoulderis formed as a curved lip.
 5. The wall block of claim 1, wherein saidchannel is adapted to receive a reinforcement member retaining bar. 6.The wall block of claim 1, wherein said front wall of said channelincludes an inwardly extending shoulder.
 7. The wall block of claim 6 1,wherein said front wall the first shoulder is formed as a curved lip. 8.The wall block of claim 1, further comprising a flange that is sized andconfigured so as to mate with a channel of another of said blocks. 9.The wall block of claim 8, wherein said flange is provided on saidbottom surface of said wall block.
 10. The wall block of claim 1,wherein said wall block is formed of a concrete material.
 11. Asegmental retaining wall system comprising: a wall block including: aninterior face for forming an interior surface of a segmental retainingwall; an exterior face for forming an exterior surface of the segmentalretaining wall; first and second sides that extend from said exteriorface to said interior face; a top surface and a bottom surface; andretaining means for retaining a reinforcement member to the wall block,said retaining means including a channel defined by a front wall, a rearwall, and a channel bottom surface and extending across one of said wallblock faces and surfaces, at least one of said front wall and rear wallhaving an inwardly extending shoulder associated therewith.
 12. Thesystem of claim 11, wherein said retaining means comprises a retainingbar that is sized and configured to fit within said channel.
 13. Thesystem of claim 12, wherein said channel extends transversely acrosssaid top surface from said first side to said second side of said wallblock.
 14. The system of claim 13, wherein said inwardly extendingshoulder is associated with said rear wall of said channel.
 15. Thesystem of claim 14, wherein said rear wall shoulder is formed as acurved lip.
 16. The system of claim 13 wherein the inwardly extendingshoulder is associated with said front wall of said channel.
 17. Thesystem of claims 11, 14, or 16 wherein said inwardly extending shoulderis integrally formed with its associated channel wall.
 18. The system ofclaim 13 wherein an inwardly extending shoulder is associated with saidfront wall of said channel and an inwardly extending shoulder isassociated with said rear wall of said channel.
 19. The system of claim18 wherein each inwardly extending shoulder is integrally formed withits associated channel wall.
 20. The system of claim 11, wherein saidwall block is formed of a concrete material.
 21. A method for forming asegmental retaining wall, said method comprising the steps of: stackinga plurality of wall blocks in aligned courses, a plurality of said wallblocks having a channel formed therein, the channel including at leastone inwardly extending shoulder; and securing at least one reinforcementmember to the wall with a retaining bar that overlaps the reinforcementmember within the channel; wherein the retaining bar in cooperation withthe channel secures the reinforcement member to the wall when tensileforces are imposed upon the reinforcement member.
 22. The method ofclaim 21, wherein the at least one inwardly extending shoulder is formedwith a curved lip.